<h2>Full example</h2>
<pre><code>#import &lt;UIKit/UIKit.h>
#import "Dependency.h"

@protocol WorldDataSource
@optional
- (NSString*)worldName;
@required
- (BOOL)allowsToLive;
@end

@interface Test : NSObject &lt;HelloDelegate, WorldDataSource> {
  NSString *_greeting;
}

@property (nonatomic, readonly) NSString *greeting;
- (IBAction) show;
@end

@implementation Test

@synthesize test=_test;

+ (id) test {
  return [self testWithGreeting:@"Hello, world!\nFoo bar!"];
}

+ (id) testWithGreeting:(NSString*)greeting {
  return [[[self alloc] initWithGreeting:greeting] autorelease];
}

- (id) initWithGreeting:(NSString*)greeting {
  if ( (self = [super init]) ) {
    _greeting = [greeting retain];
  }
  return self;
}

- (void) dealloc {
  [_greeting release];
  [super dealloc];
}

@end</code></pre>